Method for Treating Secondary Hyperparathyroidism in CKD

ABSTRACT

A stable, controlled release formulation for oral dosing of vitamin D compounds is disclosed. The formulation is prepared by incorporating one or more vitamin D compounds into a solid or semi-solid mixture of waxy materials. Oral dosage forms can be prepared by melt-blending the components described herein and filling gelatin capsules with the formulation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/109,983 filed Apr. 25, 2008, which claims the benefit of priorityunder 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No.60/913,853 filed Apr. 25, 2007. The disclosure of each priorityapplication is incorporated herein by reference.

BACKGROUND

1. Field of the Disclosure

The disclosure relates generally to controlled release pharmaceuticalcompositions. More particularly, the invention relates to acontrolled-release formulation for oral delivery of a Vitamin Dcompound.

2. Brief Description of Related Technology

Cholecalciferol and ergocalciferol (collectively are referred to as“Vitamin D”) are fat-soluble seco-steroid precursors to Vitamin Dprohormones. The Vitamin D metabolites known as 25-hydroxyvitamin D₂ and25-hydroxyvitamin D₃ (collectively referred to herein as“25-hydroxyvitamin D”) are fat-soluble steroid prohormones to Vitamin Dhormones that contribute to the maintenance of normal levels of calciumand phosphorus in the bloodstream.

Cholecalciferol and ergocalciferol are normally present at stable, lowconcentrations in human blood. Slight, if any increases in blood VitaminD levels occur after meals since unsupplemented diets have low Vitamin Dcontent, even those containing foods fortified with Vitamin D. Almostall human Vitamin D supply comes from fortified foods, exposure tosunlight or from dietary supplements, with the latter source becomingincreasingly important. Blood Vitamin D levels rise only gradually, ifat all, after sunlight exposure since cutaneous 7-dehydroxycholesterolis modified by UV radiation to pre-Vitamin D₃, which undergoes thermalconversion in the skin to cholecalciferol over a period of several daysbefore circulating in the blood. In contrast, supplements such as thosecurrently available, do cause marked increases in intraluminal, bloodand intracellular levels of Vitamin D proportional to the doseadministered.

Both cholecalciferol and ergocalciferol are metabolized into prohormonesby enzymes primarily located in the liver of the human body.Cholecalciferol is metabolized into a prohormone 25-hydroxyvitamin D₃,and ergocalciferol is metabolized into two prohormones,25-hydroxyvitamin D₂ and 24(S)-hydroxyvitamin D₂. Cholecalciferol andergocalciferol also can be metabolized into prohormones outside of theliver in certain cells, such as enterocytes, by enzymes which areidentical or similar to those found in the liver. Elevatingconcentrations of either precursor increases prohormone production;similarly, lowering precursor concentrations decreases hormoneproduction. Surges in the blood levels of cholecalciferol and/orergocalciferol (“cholecalciferol/ergocalciferol”) can transiently raiseintracellular Vitamin D concentrations, accelerating prohormoneproduction and elevating intracellular and blood prohormoneconcentrations. Surges in the blood levels of cholecalciferol and/orergocalciferol also can saturate the enzymes which produce theprohormones, causing the excess Vitamin D to be catabolized or shuntedto long-term storage in adipose tissue. Vitamin D stored in adiposetissue is less available for future conversion to prohormones. Surges inintraluminal levels of Vitamin D after ingestion of current oralsupplements can directly boost Vitamin D and prohormone concentrationsin the local enterocytes, thereby exerting “first pass” effects oncalcium and phosphorus metabolism in the small intestine.

The Vitamin D prohormones are further metabolized in the kidneys intopotent hormones. The prohormone 25-hydroxyvitamin D₃ is metabolized intoa hormone 1α,25-dihydroxyvitamin D₃ (or calcitriol); likewise,25-hydroxyvitamin D₂ and 24(S)-hydroxyvitamin D₂ are metabolized intohormones known as 1α,25-dihydroxyvitamin D₂ and1α,24(S)-dihydroxyvitamin D₂, respectively. Production of these hormonesfrom the prohormones also can occur outside of the kidney in cells whichcontain the required enzyme(s).

Surges in blood or intracellular prohormone concentrations can promoteexcessive extrarenal hormone production, leading to local adverseeffects on calcium and phosphorus metabolism. Such surges also caninhibit hepatic prohormone production from subsequent supplementalVitamin D and promote catabolism of both Vitamin D and 25-hydroxyvitaminD in the kidney and other tissues.

Blood Vitamin D hormone concentrations remain generally constant throughthe day in healthy individuals, but can vary significantly over longerperiods of time in response to seasonal changes in sunlight exposure orsustained changes in Vitamin D intake. Normally, blood levels ofcholecalciferol, ergocalciferol and the three Vitamin D prohormones arealso constant through the day, given a sustained, adequate supply ofVitamin D from sunlight exposure and an unsupplemented diet. Bloodlevels of cholecalciferol and ergocalciferol, however, can increasemarkedly after administration of currently available Vitamin Dsupplements, especially at doses which greatly exceed the amounts neededto prevent Vitamin D deficiency, rickets or osteomalacia.

The Vitamin D hormones have essential roles in human health which aremediated by intracellular Vitamin D receptors (VDR). In particular, theVitamin D hormones regulate blood calcium levels by controlling theabsorption of dietary calcium by the small intestine and thereabsorption of calcium by the kidneys. Excessive hormone levels canlead to abnormally elevated urine calcium (hypercalciuria), bloodcalcium (hypercalcemia) and blood phosphorus (hyperphosphatemia). TheVitamin D hormones also participate in the regulation of cellulardifferentiation and growth, parathyroid hormone (PTH) secretion by theparathyroid glands, and normal bone formation and metabolism. Further,Vitamin D hormones are required for the normal functioning of themusculoskeletal, immune and renin-angiotensin systems. Numerous otherroles for Vitamin D hormones are being postulated and elucidated basedon the documented presence of intracellular VDR in nearly every humantissue.

Secondary hyperparathyroidism is a disorder which develops primarilybecause of Vitamin D deficiency. It is characterized by abnormallyelevated blood levels of PTH and, in the absence of early detection andtreatment, it becomes associated with parathyroid gland hyperplasia anda constellation of metabolic bone diseases. It is a common complicationof chronic kidney disease (CKD), with rising incidence as CKDprogresses. Secondary hyperparathyroidism can also develop inindividuals with healthy kidneys, due to environmental, cultural ordietary factors which prevent adequate Vitamin D supply.

As to secondary hyperparathyroidism and its occurrence in CKD, there isa progressive loss of cells of the proximal nephrons, the primary sitefor the synthesis of the vitamin D hormones (collectively“1,25-dihydroxyvitamin D”) from 25-hydroxyvitamin D₃ and25-hydroxyvitamin D₂. In addition, the loss of functioning nephronsleads to retention of excess phosphorus which reduces the activity ofthe renal 25-hydroxyvitamin D-1α-hydroxylase, the enzyme which catalyzesthe reaction to produce the D hormones. These two events account for thelow serum levels of 1,25-dihydroxyvitamin D commonly found in patientswith moderate to severe CKD when Vitamin D supply is adequate.

Reduced serum levels of 1,25-dihydroxyvitamin D cause increased, andultimately excessive, secretion of PTH by direct and indirectmechanisms. The resulting hyperparathyroidism leads to markedlyincreased bone turnover and its sequela of renal osteodystrophy, whichmay include a variety of other diseases, such as, osteitis fibrosacystica, osteomalacia, osteoporosis, extraskeletal calcification andrelated disorders, e.g., bone pain, periarticular inflammation andMockerberg's sclerosis. Reduced serum levels of 1,25-dihydroxyvitamin Dalso can cause muscle weakness and growth retardation with skeletaldeformities (most often seen in pediatric patients).

Blood levels of 1,25-dihydroxyvitamin D are precisely regulated by afeedback mechanism which involves PTH. The renal 1α-hydroxylase (orCYP27B1) is stimulated by PTH and inhibited by 1,25-dihydroxyvitamin D.When blood levels of 1,25-dihydroxyvitamin D fall, the parathyroidglands sense this change via intracellular Vitamin D receptors andsecrete PTH. The secreted PTH stimulates expression of renal CYP27B1and, thereby, increases production of Vitamin D hormones. As bloodconcentrations of 1,25-dihydroxyvitamin D rise again, the parathyroidglands attenuate further PTH secretion. As blood PTH levels fall, renalproduction of Vitamin D hormones decreases. Rising blood levels of1,25-dihydroxyvitamin D also directly inhibit further Vitamin D hormoneproduction by CYP27B1.

PTH secretion can be abnormally suppressed in situations where blood1,25-dihydroxyvitamin D concentrations become excessively elevated, ascan occur in certain disorders such as sarcoidosis or as a result ofbolus doses of Vitamin D hormone replacement therapies. Oversuppressionof PTH secretion can cause or exacerbate disturbances in calciumhomeostasis. The parathyroid glands and the renal CYP27B1 areexquisitely sensitive to changes in blood concentrations of Vitamin Dhormones such that serum 1,25-dihydroxyvitamin D is tightly controlled,fluctuating up or down by less than 20% during any 24-hour period. Incontrast to renal production of Vitamin D hormones, extrarenalproduction is not under precise feedback control.

Blood levels of 1,25-dihydroxyvitamin D and substrate 25-hydroxyvitaminD prohormone, and regulation thereof, can also be affected by vitamin Dhormone analogs, such as 1α-hydroxyvitamin D₂ and 19-nor-1,25dihydroxyvitamin D₂.

The actions of Vitamin D hormones on specific tissues depend on thedegree to which they bind to (or occupy) the intracellular VDR in thosetissues. Cholecalciferol and ergocalciferol have affinities for the VDRwhich are estimated to be at least 100-fold lower than those of theVitamin D hormones. As a consequence, physiological concentrations ofcholecalciferol and ergocalciferol exert little, if any, biologicalactions without prior metabolism to Vitamin D hormones. However,supraphysiologic levels of cholecalciferol and ergocalciferol, in therange of 10 to 1,000 fold higher than normal, can sufficiently occupythe VDR and exert actions like the Vitamin D hormones. Similarly, theprohormones 25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃ haveessentially identical affinities for the VDR which are also estimated tobe at least 100-fold lower than those of the Vitamin D hormones. As aconsequence, physiological concentrations of 25-hydroxyvitamin D₂ and25-hydroxyvitamin D₃ have little, if any, biological actions withoutprior metabolism to Vitamin D hormones. However, supraphysiologic levelsof 25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃, in the range of 10 to1,000 fold higher than normal, can sufficiently occupy the VDR to exertactions like the Vitamin D hormones.

Production of Vitamin D prohormones declines when Vitamin D is in shortsupply, as in conditions such as Vitamin D insufficiency or Vitamin Ddeficiency (alternatively, hypovitaminosis D). Low production of VitaminD prohormones leads to low blood levels of 25-hydroxyvitamin D.Inadequate Vitamin D supply often develops in individuals who areinfrequently exposed to sunlight, have chronically inadequate intakes ofVitamin D, or suffer from conditions that reduce the intestinalabsorption of fat soluble vitamins (such as Vitamin D). It has recentlybeen reported that most individuals living in northern latitudes haveinadequate Vitamin D supplies. Left untreated, inadequate Vitamin Dsupply can cause serious bone disorders, including rickets andosteomalacia.

The Institute of Medicine (TOM) of the National Academy of Sciences hasconcluded that an Adequate Intake (AI) of Vitamin D for a healthyindividual ranges from 200 to 600 IU per day, depending on theindividual's age and sex. See Standing Committee on the ScientificEvaluation of Dietary Reference Intakes, Dietary reference intakes:calcium, phosphorus, magnesium, vitamin D, and fluoride, Washington,D.C.: National Academy Press (1997), incorporated herein by reference.The AI for Vitamin D was defined primarily on the basis of serum25-hydroxyvitamin D level sufficient to prevent Vitamin D deficiency,rickets or osteomalacia (or at least 11 ng/mL). The TOM also establisheda Tolerable Upper Intake Level (UL) for Vitamin D of 2,000 IU per day,based on evidence that higher doses are associated with an increasedrisk of hypercalciuria, hypercalcemia and related sequelae, includingcardiac arrhythmias, seizures, and generalized vascular and othersoft-tissue calcification.

Currently available oral Vitamin D supplements are far from ideal forachieving and maintaining optimal blood 25-hydroxyvitamin D levels.These preparations typically contain 400 IU to 5,000 IU of Vitamin D₃ or50,000 IU of Vitamin D₂ and are formulated for quick or immediaterelease in the gastrointestinal tract. When administered at chronicallyhigh doses, as is often required for Vitamin D repletion, these productshave significant and, often, severe limitations which are summarizedbelow.

High doses of immediate release Vitamin D supplements produce markedsurges in blood Vitamin D levels, thereby promoting: (a) storage ofVitamin D in adipose tissue, which is undesirable because stored VitaminD is less available for later hepatic conversion to 25-hydroxyvitamin D;(b) hepatic catabolism of Vitamin D to metabolites, which are lessuseful or no longer useful for boosting blood 25-hydroxyvitamin Dlevels, via 24- and/or 26-hydroxylation; and, (c) excessiveintracellular 24- or 25-hydroxylation of Vitamin D, which leads toincreased risk of hypercalciuria, hypercalcemia and hyperphosphatemia.

High doses of immediate release Vitamin D supplements also producesurges or spikes in blood and intracellular 25-hydroxyvitamin D levels,thereby promoting: (a) excessive extrarenal production of Vitamin Dhormones, and leading to local aberrations in calcium and phosphorushomeostasis and increased risk of hypercalciuria, hypercalcemia andhyperphosphatemia; (b) accelerated catabolism of both Vitamin D and25-hydroxyvitamin D by 24- and/or 26-hydroxylation in the kidney andother tissues; (c) down-regulation of hepatic production of Vitamin Dprohormones, unnecessarily impeding the efficient repletion of Vitamin Dinsufficiency or deficiency; and, (d) local aberrations in calcium andphosphorus homeostasis mediated by direct binding to VDR.

Furthermore, high doses of immediate release Vitamin D supplementsproduce supraphysiologic pharmacological concentrations of Vitamin D,e.g., in the lumen of the duodenum, promoting: (a) 25-hydroxylation inthe enterocytes and local stimulation of intestinal absorption ofcalcium and phosphorus, leading to increased risk of hypercalciuria,hypercalcemia and hyperphosphatemia; (b) catabolism of Vitamin D by 24-and/or 26-hydroxylation in the local enterocytes, causing decreasedsystemic bioavailability; and (c) absorption primarily via chylomicrons,leading to increased hepatic catabolism.

Vitamin D supplementation above the UL is frequently needed in certainindividuals; however, currently available oral Vitamin D supplements arenot well suited for maintaining blood 25-hydroxyvitamin D levels atoptimal levels given the problems of administering high doses ofimmediate release Vitamin D compounds.

Blood Vitamin D hormone concentrations also remain generally constantthrough the day in healthy individuals, but can vary significantly overlonger periods of time in response to seasonal changes in sunlightexposure or sustained alterations in Vitamin D intake. Markeddifferences in normal Vitamin D hormone levels are commonly observedamong healthy individuals, with some individuals having stableconcentrations as low as approximately 20 pg/mL and others as high asapproximately 70 pg/mL. Due to this wide normal range, medicalprofessionals have difficulty interpreting isolated laboratorydeterminations of serum total 1,25-dihydroxyvitamin D; a value of 25pg/mL may represent a normal value for one individual or a relativedeficiency in another.

Transiently low blood levels of 1,25-dihydroxyvitamin D stimulate theparathyroid glands to secrete PTH for brief periods ending when normalblood Vitamin D hormone levels are restored. In contrast, chronicallylow blood levels of 1,25-dihydroxyvitamin D continuously stimulate theparathyroid glands to secrete PTH, resulting in a disorder known assecondary hyperparathyroidism. Chronically low hormone levels alsodecrease intestinal calcium absorption, leading to reduced blood calciumconcentrations (hypocalcemia) which further stimulate PTH secretion.Continuously stimulated parathyroid glands become increasinglyhyperplastic and eventually develop resistance to regulation by vitaminD hormones. Without early detection and treatment, secondaryhyperparathyroidism progressively increases in severity, causingdebilitating metabolic bone diseases, including osteoporosis and renalosteodystrophy.

Chronically low blood levels of 1,25-dihydroxyvitamin D develop whenthere is insufficient renal CYP27B1 to produce the required supply ofVitamin D hormones, a situation which commonly arises in CKD. Theactivity of renal CYP27B1 declines as the Glomerular Filtration Rate(GFR) falls below approximately 60 ml/min/1.73 m² due to the loss offunctioning nephrons. In end-stage renal disease (ESRD), when thekidneys fail completely and hemodialysis is required for survival, renalCYP27B1 often becomes altogether absent. Any remaining CYP27B1 isgreatly inhibited by elevated serum phosphorous (hyperphosphatemia)caused by inadequate renal excretion of dietary phosphorous.

Chronically low blood levels of 1,25-dihydroxyvitamin D also developbecause of a deficiency of Vitamin D prohormones, since renal hormoneproduction cannot proceed without the required precursors. Prohormoneproduction declines markedly when cholecalciferol and ergocalciferol arein short supply, a condition often described by terms such as “Vitamin Dinsufficiency,” “Vitamin D deficiency,” or “hypovitaminosis D.”Therefore, measurement of 25-hydroxyvitamin D levels in blood has becomethe accepted method among healthcare professionals to monitor Vitamin Dstatus. Recent studies have documented that the great majority of CKDpatients have low blood levels of 25-hydroxyvitamin D, and that theprevalence of Vitamin D insufficiency and deficiency increases as CKDprogresses.

It follows that individuals most vulnerable to developing chronicallylow blood levels of 1,25-dihydroxyvitamin D are those with CKD. Most CKDpatients typically have decreased levels of renal CYP27B1 and a shortageof 25-hydroxyvitamin D prohormones. Not surprisingly, most CKD patientsdevelop secondary hyperparathyroidism. Unfortunately, early detectionand treatment of secondary hyperparathyroidism in CKD is rare, let aloneprevention.

The National Kidney Foundation (NKF) has recently focused the medicalcommunity's attention on the need for early detection and treatment ofsecondary hyperparathyroidism by publishing Kidney Disease OutcomesQuality Initiative (K/DOQI) Clinical Practice Guidelines for BoneMetabolism and Disease in Chronic Kidney Disease [Am. J. Kidney Dis.42:S1-S202, 2003)]. The K/DOQI Guidelines identified the primaryetiology of secondary hyperparathyroidism as chronically low bloodlevels of 1,25-dihydroxyvitamin D and recommended regular screening inCKD Stages 3 through 5 for elevated blood PTH levels relative tostage-specific PTH target ranges, which for Stage 3 is 35-70 pg/mL(equivalent to 3.85-7.7 pmol/L), for Stage 4 is 70-110 pg/mL (equivalentto 7.7-12.1 pmol/L), and for Stage 5 is 150-300 pg/mL (equivalent to16.5-33.0 pmol/L) (defined in K/DOQI Guideline No. 1). In the event thatscreening revealed an iPTH value to be above the ranges targeted for CKDStages 3 and 4, the Guidelines recommended a follow-up evaluation ofserum total 25-hydroxyvitamin D to detect possible Vitamin Dinsufficiency or deficiency. If 25-hydroxyvitamin D below 30 ng/mL wasobserved, the recommended intervention was Vitamin D repletion therapyusing orally administered ergocalciferol. If 25-hydroxyvitamin D above30 ng/mL was observed, the recommended intervention was Vitamin Dhormone replacement therapy using known oral or intravenous Vitamin Dhormones or analogs. The Guidelines did not recommend the concurrentapplication of Vitamin D repletion and Vitamin D hormone replacementtherapies, consistent with warnings mandated by the Food and DrugAdministration in package inserts for Vitamin D hormone replacementproducts.

The NKF K/DOQI Guidelines defined Vitamin D sufficiency as serum25-hydroxyvitamin D levels ≧30 ng/mL. Recommended Vitamin D repletiontherapy for patients with “Vitamin D insufficiency,” defined as serum25-hydroxyvitamin D of 16-30 ng/mL, was 50,000 IU per month of oralVitamin D₂ for 6 months, given either in single monthly doses or individed doses of approximately 1,600 IU per day. Recommended repletiontherapy for patients with “Vitamin D deficiency” was more aggressive:for “mild” deficiency, defined as serum 25-hydroxyvitamin D of 5-15ng/mL, the Guidelines recommended 50,000 IU per week of oral Vitamin D₂for 4 weeks, followed by 50,000 IU per month for another 5 months; for“severe” deficiency, defined as serum 25-hydroxyvitamin D below 5 ng/mL,the Guidelines recommended 50,000 IU/week of oral Vitamin D₂ for 12weeks, followed by 50,000 IU/month for another 3 months. Doses of 50,000IU per week are approximately equivalent to 7,000 IU per day.

SUMMARY

One aspect of the disclosure provides a solid or semi-solid, waxypharmaceutical formulation for controlled release of a vitamin Dcompound in the gastrointestinal tract of a subject which ingests theformulation. The formulation includes a waxy controlled release carrieragent, a lipoidic agent, an oily vehicle for the vitamin D compound, anda vitamin D compound. The formulation provides for controlled release ofthe vitamin D compound incorporated therein. The formulation preferablyis free of or essentially free of disintegrants.

In another aspect, the invention provides a controlled-release dosageform of a vitamin D compound that contains (a) a pharmacologicallyactive amount of a vitamin D compound and (b) a release-modifying agentthat controls the release rate of the vitamin D compound from the dosageform to reduce Cmaxand/or delay Tmax and/or decreaseCmax_(24hr)/C_(24hr) as described herein. Preferably both Cmax isreduced and Tmax is delayed (increased). Such controlled-release dosageforms exhibit the advantage of increased elimination half-life and/orreduced toxicity and/or improved potency (e.g., ability to administer areduced dosage of vitamin D compound, or administer less often, toachieve a similar therapeutic effect compared to an immediate releasedosage form). In some embodiments, the release-modifying agent includesa waxy controlled release carrier agent, a lipoidic agent, and an oilyvehicle for the vitamin D compound. Optionally, the release-modifyingagent and dosage forms of the invention may be free or substantiallyfree of disintegrants.

Thus, one embodiment of the invention is a method of administering anamount of a vitamin D compound to a patient such that the maximum serumconcentration of the vitamin D compound in a dose interval (Cmax) isreduced as compared to Cmax for an equivalent amount of a vitamin Dcompound administered by bolus IV injection and/or an equivalentimmediate-release, oral dosage form. Similarly, the invention provides acontrolled-release dosage form having a quantity of a vitamin D compoundthat, when administered to a patient, results in a Cmax less than Cmaxfor an equivalent amount of a vitamin D compound administered by bolusIV injection and/or by an equivalent immediate-release, oral dosageform. For example, the reduction is preferably by a factor of at least20%, 30%, 40%, 50%, 60%, 70%, or 80%.

Another embodiment of the invention is a method of administering anamount of a vitamin D compound to a patient such that the maximum changein serum concentration of a vitamin D compound in a dose interval isreduced as compared to an equivalent amount of a vitamin D compoundadministered by bolus IV injection and/or an equivalentimmediate-release, oral dosage form. Similarly, the invention provides acontrolled-release dosage form having a quantity of a vitamin D compoundthat, when administered to a patient, results in a maximum change inserum concentration of a vitamin D compound in a dose interval less thanan equivalent amount of a vitamin D compound administered by bolus IVinjection and/or by an equivalent immediate-release, oral dosage form.For example, the reduction is preferably by a factor of at least 20%,30%, 40%, 50%, 60%, 70%, or 80%.

Still another embodiment of the invention is a method of administeringan amount of a vitamin D compound to a patient such that the ratio ofthe maximum serum concentration within 24 hours after administration ofa vitamin D compound to the concentration 24 hours after administration(Cmax_(24hr)/C_(24hr)) is reduced as compared to an equivalent amount ofa vitamin D compound administered by bolus IV injection and/or anequivalent immediate-release, oral dosage form. Similarly, the inventionprovides a controlled-release dosage form having a quantity of a vitaminD compound that, when administered to a patient, results inCmax_(24hr)/C_(24hr) less than an equivalent amount of a vitamin Dcompound administered by bolus IV injection and/or by an equivalentimmediate-release, oral dosage form. For example, the reduction ispreferably by a factor of at least 20%, 30%, 40%, 50%, 60%, 70%, or 80%.

Yet another embodiment of the invention is a method of administering anamount of a vitamin D compound to a patient such that the eliminationhalf-life (t_(1/2)) of a vitamin D compound is increased as compared tot_(1/2) for an equivalent amount of a vitamin D compound administered bybolus IV injection and/or an equivalent immediate-release, oral dosageform. Similarly, the invention provides a controlled-release dosage formhaving a quantity of a vitamin D compound that, when administered to apatient, results in a t_(1/2) of a vitamin D compound greater than thatof t_(1/2) for an equivalent amount of a vitamin D compound administeredby bolus IV injection and/or by an equivalent immediate-release, oraldosage form. For example, the increase is preferably by a factor of atleast 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 200%, or 300%.

A further embodiment of the invention is a method of administering anamount of a vitamin D compound to a patient such that the time for theplasma concentration of a vitamin D compound to reach its maximum in adose interval following administration (Tmax) is increased as comparedto Tmax for an equivalent amount of a vitamin D compound administered bybolus IV injection and/or an equivalent immediate-release, oral dosageform. Similarly, the invention provides a controlled-release dosage formhaving a quantity of a vitamin D compound that, when administered to apatient, results in Tmax greater than that of an equivalent amount of avitamin D compound administered by bolus IV injection and/or by anequivalent immediate-release, oral dosage form. For example, theincrease is preferably by a factor of at least 25%, 30%, 40%, 50%, 60%,70%, 80%, 90%, 100%, 200%, 300%, 500%, or 1000%.

In various embodiments, the compositions are contemplated to beassociated with one or more benefits, such as significantly: increasingthe bioavailability of the contained vitamin D compound by promotingabsorption directly into the bloodstream rather than into the lymphaticsystem via chylomicrons; increasing the bioavailability of the containedvitamin D compound by reducing catabolism in the enterocytes of theupper small intestine; decreasing the undesirable first pass effects ofthe contained vitamin D compound on the duodenum; avoiding production ofadverse supraphysiologic surges in blood levels of the vitamin Dcompound; preventing reduction of blood concentrations of the vitamin Dcompound below optimal levels; restoring blood concentrations of thevitamin D compound to optimal levels; maintaining blood concentrationsof the vitamin D compound at such optimal levels; decreasing disruptionsin Vitamin D metabolism and related aberrations in PTH, calcium andphosphorus homeostasis; and decreasing the risk of serious side effectsassociated with vitamin D repletion and replacement, includinghypercalciuria, hypercalcemia, hyperphosphatemia, and vitamin Dtoxicity. One or more of the aforementioned benefits may be seenindependently or in combination.

For the compositions and methods described herein, preferred steps,preferred components, preferred compositional ranges thereof, andpreferred combinations of the foregoing, can be selected from thevarious examples provided herein.

Further aspects and advantages will be apparent to those of ordinaryskill in the art from a review of the following detailed description,taken in conjunction with the drawings. While the compositions andmethods are susceptible of embodiments in various forms, the descriptionhereafter includes specific embodiments with the understanding that thedisclosure is illustrative, and is not intended to limit the inventionto the specific embodiments described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For further facilitating the understanding of the present invention,twenty-seven drawing figures are appended hereto.

FIG. 1 through FIG. 8 show plots of the change in serum25-hydroxyvitamin D₃ levels over the first 24 hours post-administrationfor groups of test subjects administered oral dosage formulationsincluding 25-hydroxyvitamin D₃ according to Example 1. In addition, FIG.7 shows an overlay of comparative data for immediate and controlledrelease formulations.

FIG. 9 through FIG. 11 show plots of the change in serum25-hydroxyvitamin D₃ levels over the period of the study of Example 1for the Group 7 controlled release formulation according to theinvention, the Group 9 immediate release formulation according to theprior art, and Group 10 intravenous administration.

FIG. 12 shows an overlay plot of the data in FIG. 9 and FIG. 10 forGroups 7 and 9, respectively, in Example 1.

FIG. 13 through FIG. 18 show mean pharmacokinetic profile for miniatureswine dosed with modified and immediate release oral formulations of25-hydroxyvitamin D₃ according to Example 2.

FIG. 19 shows a comparison of pharmacokinetic profiles for MR and IRformulations of 250 μg 25-hydroxyvitamin D₃ according to Example 2.

FIG. 20 shows mean uncorrected serum 25-hydroxyvitamin D₃ concentrationversus time profiles for Groups 1 to 3 of miniature swine afteradministration of 25-hydroxyvitamin D₃ according to Example 3.

FIG. 21 through FIG. 23 show mean baseline corrected serum25-hydroxyvitamin D₃ concentration versus time profiles for Groups 1 to3 according to Example 3.

FIG. 24 shows the mean change in parathyroid hormone levels for Group 1animals from predose to day 21, and

FIG. 25 shows the mean change in parathyroid hormone levels for Group 2animals from predose to day 21, from Example 3.

FIG. 26 shows mean serum 25-hydroxyvitamin D₃ concentration versus timeprofiles for Groups 1 to 5 of Beagle dogs administered 25-hydroxyvitaminD₃ modified release capsules according to Example 4.

FIG. 27 shows a dissolution release profile for 250 μg capsulesaccording to Example 2, which showed an average release of about 72% of25-hydroxyvitamin D₃ at 24 hours.

DETAILED DESCRIPTION

As used herein, the term “Vitamin D toxicity” is meant to refer to theside effects suffered from excessively elevated Vitamin D blood levels,including one or more of nausea, vomiting, polyuria, hypercalciuria,hypercalcemia and hyperphosphatemia.

“Vitamin D insufficiency and deficiency” is generally defined as havingserum 25-hydroxyvitamin D levels below 30 ng/mL (see National KidneyFoundation guidelines, NKF, Am. J. Kidney Dis. 42:S1-S202 (2003),incorporated herein by reference).

As used herein the term “hypercalcemia” refers to condition in a patientwherein the patient has corrected serum levels of calcium above 10.2mg/dL. Normal corrected serum levels of calcium for a human are betweenabout 8.6 to 10.2 mg/dL.

As used herein the term “hyperphosphatemia” refers to a condition in apatient having normal kidney function, or Stage 3-4 CKD, wherein thepatient has serum phosphorous levels above 4.6 mg/dL. In a patient whohas Stage 5 CKD, hyperphosphatemia occurs when the patient has serumlevels above 5.5 mg/dL. Normal values for serum phosphorous in a humanare 2.5-4.5 mg/dL.

As used herein the term “over suppression of plasma iPTH” refers to acondition in a patient having normal kidney function, or Stage 1-3 CKD,wherein the patient has levels of plasma iPTH below 15 pg/mL. In apatient having Stage 4 CKD, over suppression of plasma iPTH occurs whenthe patient has levels of plasma iPTH below 30 pg/mL. In a patienthaving Stage 5 CKD, over suppression of plasma iPTH occurs when thepatient has levels of plasma iPTH below 100 pg/mL.

As used herein, the term “Vitamin D hormone replacement therapy” refersto the administration to a patient of an effective amount of an activevitamin D hormone such as 1,25-dihydroxyvitamin D₃ and/or1,25-dihydroxyvitamin D₂, optionally together with or other metabolitesand analogs of Vitamin D which can substantially occupy theintracellular VDR.

As used herein, the term “substantially constant” with respect to theserum or blood level of Vitamin D means that the release profile of thecontrolled release (defined hereinbelow) formulation should not includeincreases in total serum or blood levels of cholecalciferol andergocalciferol of greater than approximately 10 nmol/L afteradministration of a unit dose, optionally over a period of at least 4hours, 12 hours, 1 day, 2 days, 3 days, 4 days, or 5 days. The term“substantially constant” with respect to the serum or blood level of25-hydroxyvitamin D prohormones means that the release profile of anyformulation administered as detailed hereinbelow should not includetransient increases in total serum or blood levels of 25-hydroxyvitaminD of greater than approximately 3 ng/mL after administration of a unitdose. The term “substantially constant” with respect to the serum orblood level of an active vitamin D hormone preferably means that therelease profile of the controlled release formulation should not includeincreases in total serum or blood levels of 1,25-dihydroxyvitamin D ofgreater than approximately 75 pg/mL each after administration of a unitdose, optionally over a period of preferably at least 30 minutes or 4hours, etc.

As used herein, the terms “controlled release,” “sustained release,” and“modified release” are used interchangeably, and refer to the release ofthe administered vitamin D compound in a way that deviates fromimmediate release. The terms “controlled release” and “modified release”optionally include delayed release characteristics. For example, adelayed release type of controlled release formulation will becharacterized by Cmax at a time greater than Cmax for an immediaterelease formulation. As another example, the release of an administeredvitamin D (cholecalciferol and/or ergocalciferol) and/or a25-hydroxyvitamin D compound will preferably be at such a rate thattotal serum or blood levels of 25-hydroxyvitamin D are maintained orelevated above predosing levels for an extended period of time, e.g. 4to 24 hours or even longer. As another example, a sustained release typeof controlled release formulation will be characterized by release atsuch a rate that total serum or blood levels of a 1,25-dihydroxyvitaminD compound are maintained or elevated above predosing levels for anextended period of time, e.g. 20 to 40 minutes, 1 to 15 hours or evenlonger.

“Supraphysiologic” in reference to intraluminal, intracellular and bloodlevels of Vitamin D refers to a total concentration of the vitamin Dcompound markedly greater than the generally stable levels observed in aVitamin D-replete subject, animal or human patient over the course ofany 24-hour period by laboratory measurement when Vitamin Dsupplementation has been withheld for at least 30 days. “Adversesupraphysiologic surge” refers to a local or serum concentration of avitamin D compound that elicits adverse effects such as excessiveextrarenal hormone production, leading to local adverse effects oncalcium and phosphorus metabolism, inhibition of hepatic25-hydroxylation of vitamin D, increased catabolism of both Vitamin Dand 25-hydroxyvitamin D, hypercalciuria, hypercalcemia and/orhyperphosphatemia, with possible cardiovascular sequelae.

As used herein, the term “hyperparathyroidism” refers to primaryhyperparathyroidism, secondary hyperparathyroidism andhyperparathyroidism secondary to chronic kidney disease (Stage 3, 4 or5).

The term “subject” as used herein generally includes humans, mammals(e.g., dogs, cats, rodents, sheep, horses, cows, goats), veterinaryanimals and zoo animals.

It also is specifically understood that any numerical value recitedherein includes all values from the lower value to the upper value,i.e., all possible combinations of numerical values between the lowestvalue and the highest value enumerated are to be considered to beexpressly stated in this application. For example, if a concentrationrange or a beneficial effect range is stated as 1% to 50%, it isintended that values such as 2% to 40%, 10% to 30%, or 1% to 3%, etc.,are expressly enumerated in this specification. These are only examplesof what is specifically intended.

Administration of 25-hydroxyvitamin D₃ in an immediate release oralformulation has been tried as an alternative method of Vitamin Dsupplementation. This approach, which was subsequently abandoned, causedproblems as do the currently used Vitamin D supplements. Specifically,it produced surges or spikes in blood and intracellular25-hydroxyvitamin D levels. Without intending to be bound by anyparticular theory, it is believed that surges or spikes in blood andintracellular 25-hydroxyvitamin D levels promote (a) competitivedisplacement of Vitamin D hormones from the serum Vitamin D BindingProtein (DBP) and excessive delivery of the displaced hormones totissues containing VDR, and (b) transiently excessive renal andextrarenal production of Vitamin D hormones, which together led to localaberrations in calcium and phosphorus metabolism. In addition, thesesurges in blood 25-hydroxyvitamin D levels are believed to promotecatabolism of both Vitamin D and 25-hydroxyvitamin D by 24- and/or26-hydroxylation in the kidney and other tissues, down-regulation ofhepatic production of Vitamin D prohormones, unnecessarily impeding theefficient repletion of Vitamin D insufficiency or deficiency, and,additional local aberrations in calcium and phosphorus homeostasismediated by direct binding to VDR. Importantly, immediate release of25-hydroxyvitamin D₃ is believed to promote its intestinal absorptionvia a mechanism substantially involving transport to the liver inchylomicrons, rather than bound to the serum DBP. Delivery of25-hydroxyvitamin D to the liver via chylomicrons is believed tosignificantly increase the likelihood of its catabolism.

One aspect of the disclosure provides a solid or semi-solid, waxypharmaceutical formulation for controlled release of a vitamin Dcompound in the gastrointestinal tract of a subject which ingests theformulation. The formulation includes a waxy controlled release carrieragent, a lipoidic agent, an oily vehicle for the vitamin D compound, anda vitamin D compound. The formulation provides for controlled release ofthe vitamin D compound incorporated therein. The formulation is free ofor essentially free of disintegrants.

The waxy controlled release carrier provides for a formulation which issolid or semi-solid at room temperature and solid, semi-solid, or liquidat body temperature, preferably semi-solid or liquid at bodytemperature. Examples of carriers suitable for use include waxes, suchas synthetic wax, microcrystalline wax, paraffin wax, carnauba wax, andbeeswax; polyethoxylated castor oil derivatives, hydrogenated vegetableoils, glyceryl mono-, di- or tribehenates; long-chain alcohols, such asstearyl alcohol, cetyl alcohol, and polyethylene glycol; and mixtures ofany of the foregoing. Non-digestible waxy substances, such as hardparaffin wax, are preferred.

The waxy carrier preferably is present in an amount greater than about5% of the formulation, based on the total weight of the formulationexcluding any additional coatings or shells (wt %). For example, thewaxy carrier can comprise greater than 5 wt % of the formulation,greater than 10 wt % of the formulation, greater than 15 wt % of theformulation, greater than 20 wt % of the formulation, and greater than25 wt % of the formulation. The waxy carrier is preferably present in anamount less than 50 wt %, less than 40 wt %, less than 35 wt %, or lessthan 30 wt. %. Suitable ranges include 5 wt % to 35 wt %, 15 wt % to 35wt % and 20 to 30 wt %. Examples include 15 wt %, 16 wt %, 17 wt %, 18wt %, 19 wt %, 20 wt %, 21 wt %, 22 wt %, 23 wt %, 24 wt %, 25 wt %, 26wt %, 27 wt %, 28 wt %, 29 wt %, and 30 wt %.

The lipoidic agent provides for release of the vitamin D compound fromthe formulation in the gastrointestinal tract of the subject beingtreated. Without intending to be bound by any particular theory ofoperation, it is believed that the lipoidic agent can serve one or morepreferred functions such as creating a micro-emulsion of the oilyvehicle in gastrointestinal fluid; providing prolonged gastricretention, for example by bioadhesive properties such that theformulation interacts with the mucous layer of the stomach and/orintestine; and in enhancing absorption of the vitamin D compound.However, regardless of the mechanism of action, the invention is notlimited by any particular mode of operation.

The lipoidic agent components preferably are amphiphiles, in which themolecule or ion contains both hydrophilic and lipophilic portions. Thesecomponents can be defined by a numerical value based on theHydrophile/Lipophile Balance system (“HLB system”). The HLB scale is anumerical scale, extending from 0 to approximately 20, where lowernumbers denote more lipophilic and hydrophobic substances, and highernumbers denote more hydrophilic and lipophobic substances. The affinityof a compound for water, or for oily substances, is determined and itsHLB value is assigned experimentally. The HLB of the hydrophobic carrieremployed herein preferably will be in a range of about 13 to about 18.

A variety of pharmaceutically acceptable lipoidic agents may beincorporated in the formulation. The quantity of lipoidic agent presentin the formulation is preferably at least 5 wt %, at least 15 wt %, atleast 35 wt %, at least 40 wt % or at least 45 wt %. Suitable rangesinclude about 5 wt % to about 60 wt %, about 20 wt % to about 60 wt %and about 40 wt % to about 50 wt %.

In one embodiment, the lipoidic agent is a lipophilic emulsifier whichhas an HLB of less than 7 and comprises a member selected from the groupconsisting of mixed fatty acid monoglycerides; mixed fatty aciddiglycerides; mixtures of fatty acid mono- and diglycerides; lipophilicpolyglycerol esters; glycerol esters including glyceryl monooleate,glyceryl dioleate, glyceryl monostearate, glyceryl distearate, glycerylmonopalmitate, and glyceryl dipalmitate; glyceryl-lacto esters of fattyacids; propylene glycol esters including propylene glycol monopalmitate,propylene glycol monostearate, and propylene glycol monooleate; sorbitanesters including sorbitan monostearate, sorbitan sesquioleate; fattyacids and their soaps including stearic acid, palmitic acid, and oleicacid; and mixtures thereof glyceryl monooleate, glyceryl dioleate,glyceryl monostearate, glyceryl distearate, glyceryl monopalmitate, andglyceryl dipalmitate; glyceryl-lacto esters of fatty acids; propyleneglycol esters including propylene glycol monopalmitate, propylene glycolmonostearate, and propylene glycol monooleate; sorbitan esters includingsorbitan monostearate, sorbitan sesquioleate; fatty acids and theirsoaps including stearic acid, palmitic acid, and oleic acid; andmixtures thereof.

A prefrered lipoidic agent is selected from glycerides and derivativesthereof. Preferred glycerides are selected from the group consisting ofmedium or long chain glycerides, caprylocaproyl macrogolglycerides, andmixtures thereof.

Preferred medium chain glycerides include, but are not limited to,medium chain monoglycerides, medium chain diglycerides, caprylic/caprictriglyceride, glyceryl monolaurate, glyceryl monostearate,caprylic/capric glycerides, glycerylmonocaprylate, glycerylmonodicaprylate, caprylic/capric linoleic triglyceride, andcaprylic/capric/succinic triglyceride.

Monoglycerides having a low melting point are preferred for making theformulation. Preferred monoglycerides include but are not limited to,glyceryl monostearate, glyceryl monopalmitate, glyceryl monooleate,glyceryl monocaprylate, glyceryl monocaprate, glyceryl monolaurate,etc., preferably glyceryl monostearate (GMS). GMS is a naturalemulsifying agent. It is oil soluble, but poorly soluble in water. GMShas an HLB value of 3.8. Another preferred monoglyceride is glycerylmonooleate (GMO). GMO is also a natural emulsifying agent; it is oilsoluble, but poorly soluble in water, and it has an HLB value of 3.8.

In another embodiment, the glyceride is an absorption enhancer selectedfrom caprylocaproyl macrogolglycerides. Caprylocaproylmacrogolglycerides which may be employed include, but are not limitedto, polyethylene glycosylated glycerides, also known as polyglycolizedglycerides or PEGylated glycerides. PEGylaed glycerides which may beemployed in the composition include, but are not limited to, mixtures ofmonoglycerides, diglycerides, and triglycerides and monoesters anddiesters of polyethylene glycol, polyethylene glycosylated almondglycerides, polyethylene glycosylated corn glycerides, and polyethyleneglycosylated caprylic/capric triglyceride. The absorption enhancerpreferably has an HLB value from 13 to 18, more preferably from 13 to15.

One preferred absorption enhancer is known under the trade nameGELUCIRE, and is commercially available from Gattefosse Corporation,Paramus, N.J., USA. GELUCIRE is a well known excipient which is a familyof fatty acid esters of glycerol and PEG esters, also known aspolyglycolized glycerides. GELUCIRE is used in various applicationsincluding preparing sustained release pharmaceutical compositions.GELUCIRE compounds are inert, semi-solid waxy materials which areamphiphilic and are available with varying physical characteristics suchas melting point, HLB, and solubilities in various solvents. They aresurface active in nature and disperse or solubilize in aqueous mediaforming micelles, microscopic globules or vesicles. They are identifiedby their melting point/HLB value. The melting point is expressed indegrees Celsius. One or a mixture of different grades of GELUCIREexcipient may be chosen to achieve the desired characteristics ofmelting point and/or HLB value. The preferred GELUCIRE composition isGELUCIRE 44/14, a semisolid waxy material with a melting point of 44° C.and a HLB of 14.

Another preferred polyglycolyzed glyceride absorption enhancer iscaprylocaproyl macrogol-8-glyceride (CAS No. 85536-07-8 and 84963-88-2).This is a mixture of mono-, di- and triesters of glycerol and of PEG 400with medium-chain fatty acids (C₈-C₁₀) which is marketed, for example,by Gattefossé Corporation, Paramus, N.J., USA under the trade nameLABRASOL. LABRASOL has a HLB value of 14 and has the followingcomposition by weight: C₈-C₁₀ monoglycerides approximately 4%; C₈-C₁₀diglycerides approximately 17%; C₈-C₁₀ triglycerides approximately 6%;C₈-C₁₀ monoesters of PEG 400 approximately 14%; C₈-C₁₀ diesters of PEG400 approximately 36%; free PEG 400 approximately 20%; free glycerolapproximately 3%.

Preferably, the lipoidic agent includes a mixture of a lipophilicemulsifier which has an HLB of less than 7 and an absorption enhancerthat preferably has an HLB value from 13 to 18. The lipophilicemulsifier is preferably present in an amount in a range of about 20 wt% to about 50 wt %, preferably about 30 wt % to about 40 wt %, and theabsorption enhancer is preferably present in an amount of about 5 toabout 20 wt %, preferably about 8 to about 15 wt %.

The low melting points of many of the solid lipoidic compositionsprovide a means of incorporating the pharmaceutically active ingredientsin them at temperatures from about 0° C. to about 50° C. above theirrespective melting points, and then filling the melt (solution and/ordispersion) in animal or vegetable gelatin capsules. The melt solidifiesinside the capsules upon cooling to room temperature.

The oily component serves as a vehicle, preferably the main vehicle, forthe vitamin D compound. Any pharmaceutically-acceptable oil can be used.Examples include animal (e.g., fish), vegetable (e.g., soybean), andmineral oils. The oil preferably will readily dissolve the vitamin Dcompound used. Preferred oily components include non-digestible oils,such as mineral oils, particularly liquid paraffins, and squalene. Theoil vehicle preferably comprises about 10 wt % to about 50 wt % of theformulation, more preferably about 15 wt % to about 45 wt % about 20 wt% to about 40 wt %, or about 15 wt % to about 25 wt %. In one preferredembodiment, the liquid paraffin can be characterized by one or more ofthe following parameters: specific gravity about 0.88 to 0.89; kinematicviscosity (40° C.) abut 64 to about 70 cSt; molecular weight 424; %paraffinic hydrocarbons about 59; and pour point—24° C. The ratiobetween the waxy component and the oily component can be optimized inorder to achieve the desired rate of release of the vitamin D compound.Thus, if a heavier oil component is used, relatively less of the waxycomponent can be used, and if a lighter oil component is used, thenrelatively more waxy component can be used.

Any vitamin D compound suitable for prophylactic and/or therapeutic use,and combinations thereof, are contemplated for inclusion in theformulation described herein. Vitamin D, 25-hydroxyvitamin D,1,25-dihydroxyvitamin D, and other metabolites and analogs of Vitamin Dare also useful as active compounds in pharmaceutical compositions.Specific examples include, but are not limited to, Vitamin D₃(cholecalciferol), Vitamin D₂ (ergocalciferol), 25-hydroxyvitamin D₃,25-hydroxyvitamin D₂, 1α,25-dihydroxyvitamin D₃, 1α,25-dihydroxyvitaminD₂, 1α,25-dihydroxyvitamin D₄, and vitamin D analogs (including allhydroxy and dihydroxy forms), including 1,25-dihydroxy-19-nor-vitaminD₂, and 1α-hydroxyvitamin D₃. In one type of embodiment, the vitamin Dcompound includes one or more hydroxy forms, such as a combination of25-hydroxyvitamin D₃ and 25-hydroxyvitamin D₂. In some embodiments, thevitamin D compound is administered in a therapeutically effective amount(e.g., amount effective to prevent or treat hypovitaminosis D and/orsecondary hyperparathyroidism).

One aspect of the disclosure includes a composition comprising acontrolled release formulation of cholecalciferol and/or ergocalciferoland a method of administering such a formulation (in one embodiment, inhigh doses) to treat 25-hydroxyvitamin D insufficiency and deficiency ata level of efficiency heretofore unobtainable; without adversesupraphysiological surges in intraluminal, intracellular and bloodlevels of cholecalciferol, ergocalciferol and 25-hydroxyvitamin D andtheir consequences; and without serious side effects associated withVitamin D supplementation, namely Vitamin D toxicity.

The controlled release compositions are designed to containconcentrations of the cholecalciferol/ergocalciferol at or above the UL,and are prepared in such a manner as to effect controlled, preferablysubstantially constant, release of the cholecalciferol/ergocalciferolover an extended period of time. Elevating intraluminal, blood, orintracellular concentrations of either precursor increases prohormoneproduction. Furthermore, the compositions optionally can be designed fordelayed release into the ileum of the gastrointestinal tract of humansor animals. It is contemplated that in one type of embodiment thecompositions will ensure a substantially constant concentration ofcholecalciferol/ergocalciferol in the body and a more sustained bloodlevel. By providing a slow and steady release of thecholecalciferol/ergocalciferol over time, blood, intraluminal andintracellular Vitamin D concentration spikes, i.e., adversesupraphysiologic levels, are mitigated or eliminated.

Compositions comprising Vitamin D₃ at a dose of greater than 5,000 IU,or greater than 7,500 IU, or greater than 10,000 IU are contemplated.Compositions comprising a combination of cholecalciferol andergocalciferol at a unit dose of at least 1,500 IU (combined), or atleast 2,000, 2,500, 3,000, 4,000, 5,000, 6,000, 7,000, 7,500, 8,000,9,000, 10,000, 11,000, 12,000 or 12,500 IU are contemplated. Such unitdoses less than 200,000 IU, or less than 100,000 or 75,000 or 50,000 IUare also contemplated.

The invention also contemplates that doses may be given at intervals ofonce a day, once every other day, three times a week, twice a week,weekly, or every 2 weeks. The cumulative dose taken each time may be1,500 IU (cholecalciferol and ergocalciferol separately or combined), orat least 2,000, 2,500, 3,000, 4,000, 5,000, 6,000, 7,000, 7,500, 8,000,9,000, 10,000, 11,000, 12,000 or 12,500 IU. Such doses less than 200,000IU, or less than 100,000 or 75,000 or 50,000 IU are also contemplated.Such doses are preferred for use with adult humans.

The cholecalciferol and ergocalciferol can be included in any ratio,e.g., 9:1 to 1:9. Ratios including, but not limited to 1:1, greater than1:1 cholecalciferol:ergocalciferol, and less than 1:1cholecalciferol:ergocalciferol, are contemplated to be useful in variousembodiments.

For example, a combination of 1,500 IU cholecalciferol and 1,500 IUergocalciferol in a single unit dose capsule and/or in a daily dose iscontemplated. Also contemplated are combinations of 1,000 IUcholecalciferol with 1,000 IU ergocalciferol in a single unit dosecapsule and/or in a daily dose and 2,000 IU cholecalciferol with 2,000IU ergocalciferol in a single unit dose capsule and/or in a daily dose.The initial dosing regimen of such a unit dose capsule can be based onbaseline serum 25(OH)D (ng/ml) [nmol/L] levels, for example as detailedin Table 1 below for a combination of 1,500 IU cholecalciferol and 1,500IU ergocalciferol in a single unit dose capsule.

TABLE 1 Serum 25(OH)D (ng/ml) [nmol/L] Description Dose Duration Comment<5 [12] severe vitamin D 2 capsules daily 8 weeks measure 25(OH)Ddeficiency levels  5-15 [12-37] mild vitamin D 2 capsules daily 6 weeksmeasure 25(OH)D deficiency levels 16-30 [40-75] vitamin D 2 capsulesdaily 2 weeks measure 25(HO)D insufficiency levels ≧30 [≧75] vitamin D 1capsule daily continuous measure 25(OH)D sufficiency levels/6 months

To maintain serum concentrations of 25(OH)D at 30 ng/mL or above, onesuch capsule can be administered per day to adult patients.

The invention also includes compositions comprising oral formulations of25-hydroxyvitamin D₂ and/or 25-hydroxyvitamin D₃ (“25-hydroxyvitaminD₂/25-hydroxyvitamin D₃”) and methods of administering such formulationsto treat 25-hydroxyvitamin D insufficiency and deficiency withoutsupraphysiological surges in intraluminal, intracellular and bloodlevels of 25-hydroxyvitamin D and their consequences; without causingsubstantially increased catabolism of the administered 25-hydroxyvitaminD; and, without causing serious side effects associated with Vitamin Dsupplementation, namely Vitamin D toxicity.

The controlled release compositions intended for oral administration inaccordance with the invention preferably are designed to containconcentrations of the 25-hydroxyvitamin D₂/25-hydroxyvitamin D₃ of 1 to1000 μg per unit dose and are prepared in such a manner as to effectcontrolled or substantially constant release of the 25-hydroxyvitaminD₂/25-hydroxyvitamin D₃, optionally into the ileum of thegastrointestinal tract, of humans or animals over an extended period oftime. Preferred dosages include 1 to 1000 μg per unit dose, 1 to 600 μg,1 to 400 μg, 1 to 200 μg, 1 to 100 μg, 5 to 90 μg, 30 to 80 μg, 20 to 60μg, 30 to 60 μg, 35 to 50 μg, 5 to 50 μg, and 10 to 25 μg, for example20 μg, 25 μg, 30 μg, 40 μg, 50 μg, 60 μg, 70 μg, 80 μg, 90 μg, and 100μg. The compositions may provide substantially increased absorption of25-hydroxyvitamin D via transport on DBP and decreased absorption viatransport in chylomicrons. The compositions may provide maintenance ofsubstantially constant blood levels of 25-hydroxyvitamin D during the24-hour post-dosing period. By providing a gradual, sustained and directrelease of the 25-hydroxyvitamin D₂/25-hydroxyvitamin D₃ and absorptionpreferentially to circulating DBP (rather than to chylomicrons), blood,intraluminal and intracellular 25-hydroxyvitamin D concentration spikes,i.e., supraphysiologic levels and related unwanted catabolism can bemitigated or eliminated. Furthermore, by providing a gradual andsustained release, serum levels of 25-hydroxyvitamin D can be increasedand maintained more predictably than by administration of immediaterelease oral formulations, allowing for a consistent dosage and reducingor eliminating the need for frequent patient monitoring.

In one preferred class of embodiments, the modified release formulationreleases at least 70%, more preferably at least 80% of the vitamin Dcompound within the first 24 hours after dosing, for example about 72%.

Advantageously, 25-hydroxyvitamin D₂, 25-hydroxyvitamin D₃ orcombinations thereof together with other therapeutic agents can beorally or intravenously administered in accordance with the abovedescribed embodiments in dosage amounts of from 1 to 100 μg per day,with the preferred dosage amounts of from 5 to 50 μg per day, forexample about 10 to 25 μg. Preferred doses will provide an average risein serum 25-hydroxyvitamin D₃ of about 1 to 3 ng/mL.

In embodiments, the method is contemplated to include administering aformulation described herein to raise and preferably also maintain blood1,25-dihydroxyvitamin D levels at 25 pg/mL, 30 pg/mL, or higher, e.g.25-65 pg/mL for an extended period, for example at least one month, atleast three months, at least six months, or longer.

In one aspect, a method for lowering or maintaining lowered serumparathyroid hormone in human patients includes administering to saidpatients an effective amount of an active vitamin D hormone such as1,25-dihydroxyvitamin D₂ according to the disclosure herein to lower ormaintain lowered serum parathyroid hormone levels, preferably an amountthat lowers PTH levels by at least 30%, or alternatively the amountneeded to reduce serum levels of PTH to the target range for the CKDstage (e.g., for Stage 3 is 35-70 pg/mL (equivalent to 3.85-7.7 pmol/L),for Stage 4 is 70-110 pg/mL (equivalent to 7.7-12.1 pmol/L), and forStage 5 is 150-300 pg/mL (equivalent to 16.5-33.0 pmol/L) (defined inK/DOQI Guideline No. 1)).

In another aspect, the method includes administering to a patientsuffering from hyperparathyroidism secondary to chronic kidney disease(Stage 3, 4 or 5) an effective amount of an active vitamin D hormonesuch as 1,25-dihydroxyvitamin D₂ according to the disclosure herein tolower the serum PTH level.

The dosage of a 1,25-dihydroxyvitamin D for oral administrationgenerally is about 0.1 μg per week to 100 μg per week, preferably about0.7 μg per week to about 70 μg per week, which can be split into dailyor other periodic doses, such as three times per week for administrationconcomitant with hemodialysis. In exemplary embodiments, an oral dosageequivalent to about 1, 2, 3, 4, 5, 6, 7, 8 or 9 μg per day iscontemplated.

Generally, a 1,25-dihydroxyvitamin D compound is dispensed by unitdosage form comprising about 0.1 μg to about 10 μg per unit dosage, forexample about 1 μg to about 4 μg, about 2 μg to about 10 μg, or about 3μg to about 5 μg.

Administration of a vitamin D hormone, such as 1,25-dihydroxyvitamin D₂,as described herein also allows for the efficient and predictabledelivery of a predetermined dosage of vitamin D hormone to a patient.The temporal and quantitative availability of the active vitamin Dhormone is not dependent on activation in the liver or other metabolism.Accordingly, lower dosages, compared to delivery by other means, areconsidered possible in order to achieve equivalent effects, whileoptionally or preferably avoiding or reducing side effects, as describedabove.

The dosages described herein are contemplated for any of the therapeuticmethods described herein. It will be appreciated that the actualpreferred amount of a vitamin D compound in a specific case will varyaccording the particular compositions formulated, the mode ofapplication, and the particular situs being treated. Dosages can bedetermined using conventional considerations, e.g., by customarycomparison of the differential activity of the hormone and of a knownagent, e.g. by means of an appropriate conventional pharmacologicalprotocol.

The specific doses for each particular patient can depend on a widevariety of factors, for example, on the age, body weight, general stateof health, sex, on the diet, on the timing and mode of administration,on the rate of excretion, and on medicaments used in combination and theseverity of the particular disorder to which the therapy is applied.

Patients in need of vitamin D supplementation include healthy subjectsand subjects at risk for vitamin D insufficiency or deficiency, forexample, subjects with Stage 1, 2, 3, 4 or 5 CKD; infants, children andadults that do not drink vitamin D fortified milk (e.g. lactoseintolerant subjects, subjects with milk allergy, vegetarians who do notconsume milk, and breast fed infants); subjects with rickets; subjectswith dark skin (e.g., in the U.S., 42% of African American women between15 and 49 years of age were vitamin D deficient compared to 4% of whitewomen); the elderly (who have a reduced ability to synthesize vitamin Dand also are more likely to stay indoors); institutionalized adults (whoare likely to stay indoors, including subjects with Alzheimer's diseaseor mentally ill); subjects who cover all exposed skin (such as membersof certain religions or cultures); subjects who always use sunscreen(e.g., the application of sunscreen with a Sun Protection Factor (SPF)value of 8 reduces production of vitamin D by 95%, and higher SPF valuesmay further reduce vitamin D); subjects with fat malabsorption syndromes(including but not limited to cystic fibrosis, cholestatic liverdisease, other liver disease, gallbladder disease, pancreatic enzymedeficiency, Crohn's disease, inflammatory bowel disease, sprue or celiacdisease, or surgical removal of part or all of the stomach and/orintestines); subjects with inflammatory bowel disease; subjects withCrohn's disease; subjects who have had small bowel resections; subjectswith gum disease; subjects taking medications that increase thecatabolism of vitamin D, including phenyloin, fosphenyloin,phenobarbital, carbamazepine, and rifampin; subjects taking medicationsthat reduce absorption of vitamin D, including cholestyramine,colestipol, orlistat, mineral oil, and fat substitutes; subjects takingmedications that inhibit activation of vitamin D, includingketoconazole; subjects taking medications that decrease calciumabsorption, including corticosteroids; subjects with obesity (vitamin Ddeposited in body fat stores is less bioavailable); subjects withosteoporosis; and/or postmenopausal women. According to the Institute ofMedicine's report on the Dietary Reference Intakes for vitamin D, foodconsumption data suggest that median intakes of vitamin D for bothyounger and older women are below current recommendations; data suggestthat more than 50% of younger and older women are not consumingrecommended amounts of vitamin D.

Optionally excluded from the methods of the invention described hereinare therapeutic treatment of subjects suffering from renalosteodystrophy (including osteomalacia and osteitis fibrosa cystica).

In other aspects, the compositions and methods of the invention areuseful for prophylactic or therapeutic treatment of vitamin D-responsivediseases, i.e., diseases where vitamin D, 25-hydroxyvitamin D or activevitamin D (e.g., 1,25-dihydroxyvitamin D) prevents onset or progressionof disease, or reduces signs or symptoms of disease. Such vitaminD-responsive diseases include cancer (e.g., breast, lung, skin,melanoma, colon, colorectal, rectal, prostate and bone cancer).1,25-dihydroxyvitamin D has been observed to induce cell differentiationand/or inhibit cell proliferation in vitro for a number of cells.Vitamin D-responsive diseases also include autoimmune diseases, forexample, type I diabetes, multiple sclerosis, rheumatoid arthritis,polymyositis, dermatomyositis, scleroderma, fibrosis, Grave's disease,Hashimoto's disease, acute or chronic transplant rejection, acute orchronic graft versus host disease, inflammatory bowel disease, Crohn'sdisease, systemic lupus erythematosis, Sjogren's Syndrome, eczema andpsoriasis, dermatitis, including atopic dermatitis, contact dermatitis,allergic dermatitis and/or chronic dermatitis. Vitamin D-responsivediseases also include other inflammatory diseases, for example, asthma,chronic obstructive pulmonary disease, polycystic kidney disease,polycystic ovary syndrome, pancreatitis, nephritis, hepatitis, and/orinfection. Vitamin D-responsive diseases have also been reported toinclude hypertension and cardiovascular diseases. Thus, the inventioncontemplates prophylactic or therapeutic treatment of subjects at riskof or suffering from cardiovascular diseases, for example, subjects withatherosclerosis, arteriosclerosis, coronary artery disease,cerebrovascular disease, peripheral vascular disease, myocardialinfarction, myocardial ischemia, cerebral ischemia, stroke, congestiveheart failure, cardiomyopathy, obesity or other weight disorders, lipiddisorders (e.g. hyperlipidemia, dyslipidemia including associateddiabetic dyslipidemia and mixed dyslipidemia hypoalphalipoproteinemia,hypertriglyceridemia, hypercholesterolemia, and low HDL (high densitylipoprotein)), metabolic disorders (e.g. Metabolic Syndrome, Type IIdiabetes mellitus, Type I diabetes mellitus, hyperinsulinemia, impairedglucose tolerance, insulin resistance, diabetic complication includingneuropathy, nephropathy, retinopathy, diabetic foot ulcer andcataracts), and/or thrombosis.

Diseases which can benefit from a modulation in the levels of vitamin Dcompounds, include, but are not limited to: (i) in theparathyroid—hypoparathyroidism, Pseudohypo-parathyroidism, secondaryhyperparathyroidism; (ii) in the pancreas—diabetes; (iii) in thethyroid—medullary carcinoma; (iv) in the skin—psoriasis; wound healing;(v) in the lung—sarcoidosis and tuberculosis; (vi) in the kidney—chronickidney disease, hypophosphatemic VDRR, vitamin D dependent rickets;(vii) in the bone—anticonvulsant treatment, fibrogenisis imperfectaossium, osteitis fibrosa cystica, osteomalacia, osteoporosis,osteopenia, osteosclerosis, renal osteodytrophy, rickets; (viii) in theintestine—glucocorticoid antagonism, idopathic hypercalcemia,malabsorption syndrome, steatorrhea, tropical sprue; and (ix) autoimmunedisorders.

In embodiments of the invention, the disease that benefits from amodulation in the levels of vitamin D compounds are selected fromcancer, dermatological disorders (for example psoriasis), parathyroiddisorders (for example hyperparathyroidism and secondaryhyperparathyroidism), bone disorders (for example osteoporosis) andautoimmune disorders.

The formulation can be prepared by procedures well known to one ofordinary skill in the art. Typically, the pharmaceutically acceptablewaxes, lipoidic agents, and oils are melted, if necessary, to provide aflowable liquid thereby making it easier to obtain a homogeneousmixture. The Vitamin D compound is added to the thus liquid carrier, forexample dissolved in an alcohol such as anhydrous ethanol, and theingredients are mixed to provide a homogeneous mixture. The mixture canbe cooled and stored prior to later division into unit dosage forms,such as filled gelatin capsules.

In one preferred method, a portion of the oil vehicle, solid wax, and alipophilic emulsifier are heated to a relatively high temperature (e.g.,65° C.) and mixed prior to adding an absorption enhancer, followed byadditional mixing until homogenous, then cooling to an intermediateelevated temperature (e.g., 50° C. to 55° C.). In a separate vessel, anantioxidant preservative and the remainder of the oil vehicle are mixedand heated to an intermediate elevated temperature (e.g., 50° C.), thencombined and mixed with the wax mixture until a homogenous solution isobtained. Next, a solution of vitamin D compound in alcohol is combinedwith the homogenous waxy solution, mixed until a homogenous solution isobtained, preferably filled into capsules, and then cooled to roomtemperature. In another preferred method, a portion of the oil vehicle,solid wax, and a lipophilic emulsifier are heated at a temperature of55° C. to 60° C. and mixed prior to adding an absorption enhancer,followed by additional mixing until homogenous. In a separate vessel, anantioxidant preservative and the remainder of the oil vehicle are mixedand heated to a temperature of 55° C. to 60° C., then combined and mixedwith the wax mixture until a homogenous solution is obtained. Next, asolution of vitamin D compound in alcohol is combined with thehomogenous waxy solution, mixed until a homogenous solution is obtained,preferably filled into capsultes, and then cooled to room temperature.

The formulation preferably is placed in capsules prior to administrationto the patient in need of treatment. Such capsules may be hard or soft,and soft capsules are preferred. The formulation may be filled intogelatin capsules using standard capsule filling machinery, such as bymelting the formulation and injection filling it into soft capsuleshells.

The formulation and methods of use and making are contemplated toinclude embodiments including any combination of one or more of theadditional optional elements, features, and steps further describedbelow, unless stated otherwise.

Thus, in one type of embodiment, the formulation further includes apreservative, such as an antioxidant. Butylated hydroxytoluene (BHT) ispreferred.

In another type of embodiment, the vitamin D compound is administered incombination with one or more other therapeutic agents.

If the vitamin D compound is administered in combination with one ormore other therapeutic agents, the proportions of each of the compoundsin the combination being administered will be dependent on theparticular disease state being addressed. For example, one may choose toorally administer 25-hydroxyvitamin D₂ and/or 25-hydroxyvitamin D₃ withone or more calcium salts (intended as a calcium supplement or dietaryphosphate binder), bisphosphonates, calcimimetics, nicotinic acid, iron,phosphate binders, cholecalciferol, ergocalciferol, active Vitamin Dsterols, glycemic and hypertension control agents, variousantineoplastic agents and inhibitors of CYP24 and other cytochrome P450enzymes that can degrade vitamin D agents. In addition, one may chooseto intravenously administer 25-hydroxyvitamin D₂ and/or25-hydroxyvitamin D₃ with cholecalciferol, ergocalciferol, activeVitamin D sterols, glycemic and hypertension control agents, variousantineoplastic agents and inhibitors of CYP24 and other cytochrome P450enzymes that can degrade vitamin D agents. In practice, higher doses ofthe compounds of the present invention are used where therapeutictreatment of a disease state is the desired end, while the lower dosesare generally used for prophylactic purposes, it being understood thatthe specific dosage administered in any given case will be adjusted inaccordance with the specific compounds being administered, the diseaseto be treated, the condition of the subject and the other relevantmedical facts that may modify the activity of the drug or the responseof the subject, as is well known by those skilled in the art.

As described above, the formulation is preferably filled into gelatincapsules, but it may also be administered in neat form, or with one ormore external coating layers, such as an enteric coating. It is alsocontemplated that the formulation can be pressed into tablets, and insuch cases one or more tablet pressing excipients may be included.

In the compositions and methods described herein, preferred steps,preferred components, preferred compositional ranges thereof, andpreferred combinations of the foregoing, can be selected from thevarious specific examples provided herein. For example, a preferredformulation includes 25-hydroxyvitamin D (e.g. 25-hydroxyvitamin D₃, forexample about 0.1 wt % (e.g. 0.12 wt %)), about 2 wt % (e.g., 2.32 wt %)ethanol, about 10 wt % (e.g., 9.75 wt %) GELUCIRE 44/14, about 27 wt %(e.g., 27.51 wt. %) hard paraffin, about 38 wt % (e.g., 37.85 wt %) GMS,about 22 wt % (e.g., 22.43 wt %) mineral oil, and optionally a smallamount of preservative (e.g., 0.02 wt % BHT). A variation on thisformulation will include about 20% hard paraffin and about 29% mineraloil.

Specifications for still another preferred embodiment of a capsule, anda 50 μg embodiment, are shown in Table 2 below.

TABLE 2 Milligram per Ingredient capsule % w/w 25-hydroxyvitamin D₃0.040 0.024 Dehydrated ethanol 4.22 2.48 Hard Paraffin 33.97 19.98Mineral Oil 50.80 29.88 GELUCIRE 44/14 16.59 9.76 GMS 64.35 37.85 BHT0.034 0.020 Total 170.00 100.00

EXAMPLES

The following Examples illustrate specific formulations and methods fortheir preparation. The Examples are provided for illustration and arenot intended to limit the scope of the invention.

Example 1 Modified Release Formulations

Nine oral vitamin D formulations were prepared according to Table 3below by homogeneously mixing the identified components in the amountsshown and filling the mixtures into hard gelatin capsules. Formulation 9is an immediate-release formulation according to the prior art, whereinMIGLYOL 812N is the trade name for caprylic/capric triglycerides,available from CONDEA Chemie GmbH of Cranford, N.J., USA. Theformulations were administered to groups of Yucatan miniature swine(about 10 kg), in single doses equivalent to 250 μg of 25-hydroxyvitaminD₃. Each group included five animals. An equivalent 250 μg of25-hydroxyvitamin D₃ was administered to a tenth group of five Yucatanminiature swine via intravenous injection.

TABLE 3 25-(OH)- In- Vitamin Carnauba GELUCIRE Soybean Hard LiquidMIGLYOL gredient D₃ Ethanol Wax 44/14 LABRASOL Oil BHT Paraffin GMS GMOParaffin 812N Total 1 % w/w 0.12 2.32 14.63 9.75 9.75 63.40 0.02 100mg/Cap 0.25 4.75 30.00 20.00 20.00 130.00 0.04 205 2 % w/w 0.12 2.3227.50 9.75 9.75 50.53 0.02 100 mg/Cap 0.25 4.75 56.40 20.00 20.00 103.600.04 205 3 % w/w 0.12 2.32 14.63 9.75 37.85 35.31 0.02 100 mg/Cap 0.254.75 30.00 20.00 77.60 72.40 0.04 205 4 % w/w 0.12 2.32 11.51 8.10 3.1274.80 0.02 100 mg/Cap 0.25 4.75 23.60 16.60 6.40 153.36 0.04 205 5 % w/w0.12 2.32 9.75 0.02 14.63 37.85 35.31 100 mg/Cap 0.25 4.75 20.00 0.0430.00 77.60 72.40 205 6 % w/w 0.12 2.32 9.75 0.02 14.63 9.75 9.75 53.65100 mg/Cap 0.25 4.75 20.00 0.04 30.00 20.00 20.00 110.00 205 7 % w/w0.12 2.32 9.75 0.02 27.51 37.85 22.43 100 mg/Cap 0.25 4.75 20.00 0.0456.40 77.60 46.00 205 8 % w/w 0.12 2.32 0.02 9.75 9.75 9.75 68.23 100mg/Cap 0.25 4.75 0.04 20.00 20.00 20.00 139.96 205 9 % w/w 0.12 2.320.02 97.54 100 mg/Cap 0.25 4.75 0.04 199.96 205

Blood was collected pre-dose, and at 0.5, 1, 2, 4, 6, 8, 12, 24, 48, 96,168, 240, 336, 432, 504, 576, and 672 hours post dosing. Serum25-hydroxyvitamin D₃ levels were assayed by Liquid Chromatography/MassSpectrometry/Mass Spectrometry (LC MS/MS).

Plots of the change in serum 25-hydroxyvitamin D₃ levels over the first24 hours for Groups 1-8 are shown in FIG. 1 through FIG. 8. In addition,the data for the Group 9 immediate release control are plotted with theGroup 7 data in FIG. 7. The concentration profiles show that the Group 7formulation according to the invention (a) produced a graduallyincreasing and sustained rise in serum 25-hydroxyvitamin D₃ levels overthe first 24 hours, and (b) avoided a surge in 25-hydroxyvitamin D₃levels.

FIG. 9 through FIG. 11 show plots of the change in serum25-hydroxyvitamin D₃ levels over the period of the study for Groups 7,9, and 10, respectively. FIG. 12 shows an overlay plot of the data inFIG. 9 and FIG. 10 for Groups 7 and 9, respectively.

The concentration profiles shows that the Group 7 formulation accordingto the invention produced a gradually increasing rise in serum25-hydroxyvitamin D₃ levels, avoided a surge in 25-hydroxyvitamin D₃levels, and produced a sustained increase of serum 25-hydroxyvitamin D₃over a long period of time.

In vitro dissolution tests of the same formulations (dissolution media:0.056 lipase in Ctab/NaH₂PO₄ buffer, pH 6.8) over a period of 120minutes showed results generally consistent with the in vivo data (e.g.,formulations 2 and 7 showed a more gradual and incomplete rise in %dissolution, whereas the immediate release control showed 100% releasewithin 30 minutes).

The data in Table 4 below show various pharmacokinetic parametersproduced in the test subjects by administration of the Group 7formulation according to the invention compared to the Group 9 prior artimmediate release formulation and the Group 10 IV injectionadministration. The data demonstrate that the Group 7 formulationaccording to the invention avoided a concentration spike, provided amaximum concentration at a time much later than the immediate releasedosage form and the intravenous injection, and provided a longerclearance half life than the comparable immediate release dosage form.The Group 7 formulation according to the invention resulted in a slowerelimination of the 25-hydroxyvitamin D₃ administered from systemiccirculation compared to Group 9.

A single dose of 250 μg 25-hydroxyvitamin D₃ administered according tothe Group 7 formulation of the invention to mini-pigs (about 10 kg)resulted in an approximately 40 ng/ml rise in serum 25-hydroxyvitaminD₃. A single dose of 50 μg 25-hydroxyvitamin D₃ to a human (about 60 kg)is expected to increase serum levels of 25-hydroxyvitamin D₃ by about1.4 ng/ml.

TABLE 4 AUC AUC (0-672 hr) (0-INF) Cmax Tmax T½ Cmax_(24hr)/C_(24hr) BAGrp (ng/ml hr) (ng/ml hr) (ng/ml) (hr) (hr) (ng/ml) (%) 7 AVG 8062.610425.7 39.5 39.2 120.9 1.42 STD 6259.2 6676.4 11.4 35.4 27.9 0.93 62.7% RSD 77.63 64.0 28.7 90.2 23.0 65.41 9 AVG 12074.5 12201.4 204.8 3.571.5 2.23 STD 1028.0 1099.0 12.6 1.0 16.9 0.49 73.4 % RSD 8.5 9.0 6.128.6 23.7 22.11 10 AVG 15038.0 16616.1 154.9 1.5 132.4 2.12 STD 2903.43646.2 71.1 1.7 18.7 0.84 100.0 % RSD 19.3 21.9 45.9 112.0 14.1 39.67

Comparative Cmax, Tmax, and bioavailability data for the formulations ofGroups 1-6 and 8 are shown in Table 5 below.

TABLE 5 C_(max) T_(max) BA Group (ng/ml) (hr) (%) 1 AVG 105.9 7.0 69.1STDEV 33.0 9.6 % RSD 31.2 137.0 2 AVG 29.7 12.8 25.3 STDEV 15.2 10.4 %RSD 51.2 80.9 3 AVG 109.4 4.0 84.1 STDEV 22.6 0.0 % RSD 20.6 0.0 4 AVG162.1 4.8 97.2 STDEV 30.3 1.8 % RSD 18.7 37.3 5 AVG 90.8 3.2 70.7 STDEV22.7 1.1 % RSD 24.9 34.2 6 AVG 99.9 3.2 72.3 STDEV 24.3 1.8 % RSD 24.455.9 8 AVG 91.5 3.6 70.2 STDEV 41.2 0.9 % RSD 45.0 24.8

Example 2 Pharmacokinetic Studies in Miniature Swine with Oral Capsules

The purpose of the study was to assess the systemic absorption of25-hydroxyvitamin D₃ in male Yucatan swine (˜45 kg body weight)following the administration of: a) 1×250 μg 25-hydroxyvitamin D₃modified release (MR) capsule, b) 2×250 μg MR capsules, c) 4×250 μg MRcapsules, d) 1×1000 μg MR capsule, e) 1×250 μg immediate release (IR)25-hydroxyvitamin D₃ capsule, and f) 1×250 μg MR capsule administered on3 consecutive days.

The MR formulations were prepared based on the formulation of Example 1,Group 7, above. In the case of the 1000 μg MR capsule, the higherconcentration of 25-hydroxyvitamin D₃ was offset by a relative decreasein ethanol.

To prepare the IR formulation 25-hydroxyvitamin D₃ (0.12% wt/wt; 250 μgper capsule) was dissolved in ethanol USP (2.32% wt/wt; solublizer) andmixed with corn oil USP, (97.54% wt/wt; main vehicle) and butylatedhydroxytoluene (0.02% wt/wt; antioxidant). The corn oil solution (205mg) was filled into size 0 two piece hard gelatin capsules.

Eight male Yucatan miniature swine per group were each administered adose based on the dosing schedule in Table 6 below. Blood was collectedfrom animals prior to first dose and at 0.5, 1, 2, 4, 6, 8, 10, 12, 24,48, 72, and 96 hrs following first dose. Animals in Group 6 wereadministered a second and third dose immediately following thecollection of the 24 and 48 hr blood samples, respectively.25-hydroxyvitamin D₃ was assayed in all the collected samples. Ionizedcalcium and total calcium were determined in samples collected fromanimals in Group 1 and Group 5 at the following time points: pre doseand at 0.5, 1, 2, 4, 6, 8, 10, 12, 24, 48, 72, and 96 hrs followingfirst dose.

TABLE 6 Number/ Group Gender of Dose ID Animals Route Dose/Animal 1M8/male Oral 1 capsule × 250 μg, modified release 2M 8/male Oral 2capsules × 250 μg, modified release 3M 8/male Oral 4 capsules × 250 μg,modified release 4M 8/male Oral 1 capsule × 1000 μg, modified release 5M8/male Oral 1 capsule × 250 μg, immediate release 6M 8/male Oral 3capsules × 250 μg, modified release

25-hydroxyvitamin D₃ in swine serum was assayed using solid-phaseextraction (SPE) with high performance liquid chromatography with tandemmass spectrometry (LC-MS/MS) detection. Serum samples were baselinecorrected to exclude endogenous concentrations of 25-hydroxyvitamin D₃from the pharmacokinetic analysis. To achieve this pre-dose25-hydroxyvitamin D₃ concentration of each animal were subtracted fromeach of its post dose concentrations. Serum samples below the 1 ng/ml(lower limit of quantitation) were assigned a value of zero.

Pharmacokinetic parameters are reported in Table 7.

TABLE 7 AUC_((0-24 hr)) AUC_((0-t)) C_(max) C_(24 hr) T_(max) Group(ng/ml hr) (ng/ml hr) (ng/mL) (ng/mL) (hours) C_(max)/C_(24 hr)C_(max)/AUC_((0-24 hr)) 1 AVG 417.81 1838.73 31.58 26.08 26.50 1.28 0.08STDEV 121.63 709.85 7.63 9.87 22.42 0.28 0.02 % RSD 29.1 38.6 24.1 37.984.6 22.0 29.3 2 AVG 619.30 2862.75 47.86 36.80 30.50 1.42 0.10 STDEV315.95 528.10 14.51 10.86 23.24 0.38 0.08 % RSD 51.0 18.4 30.3 29.5 76.226.4 79.4 3 AVG 1059.99 4321.75 72.29 58.00 25.50 1.28 0.07 STDEV 232.36894.26 18.76 18.35 23.22 0.27 0.008 % RSD 21.9 20.7 26.0 31.6 91.1 21.111.5 4 AVG 642.79 2608.04 52.19 39.41 25.71 1.61 0.12 STDEV 392.481574.53 20.41 15.97 20.89 0.35 0.08 % RSD 61.1 60.4 39.1 40.5 81.3 21.567.2 5 AVG 812.51 2374.50 49.73 30.97 5.75 1.63 0.06 STDEV 115.47 266.959.22 4.76 1.28 0.34 0.005 % RSD 14.2 11.2 18.5 15.4 22.3 21.0 8.7

Dose normalized pharmacokinetic parameters for Groups 1 to 3 arereported in Table 8.

TABLE 8 Group 1 Group 2 Group 3 PK Parameters AVG STDEV % RSD AVG STDEV% RSD AVG STDEV % RSD AUC_((0-t)) 7.35 2.84 38.61 5.73 1.06 18.45 4.320.89 20.69 (ng/ml hr)/μg C_(max) (ng/mL)/μg 0.13 0.03 24.15 0.10 0.0330.33 0.07 0.02 25.96 C_(24 hr) (ng/mL)/μg 0.10 0.04 37.85 0.07 0.0229.50 0.06 0.02 31.64 AUC_((0-24 h)) 1.67 0.49 29.11 1.24 0.63 51.021.06 0.23 21.92 (ng/ml hr)/μg

For the groups administered 1, 2 and 4 capsules (250 μg MR capsules),there was an increase in exposure as a function of dose. Doseproportional exposure occurred at the 1×250 μg and 2×250 μg doses, whileslightly less than proportional exposure was observed between 2×250 μgand 4×250 μg doses. The mean time at which maximum concentration wasachieved (T_(max)) was between 25.5 to 30.5 hrs.

Comparison of exposure from a single capsule (1×1000 μg) versus fourcapsules (4×250 μg) indicated higher exposure in animals dosed withmultiple capsules. Dose independent parameters, such as mean T_(max),were similar for both dosing strategies.

The comparison of the modified release formulation of 25-hydroxyvitaminD₃ (MR) (Group 1) to the IR formulation (Group 5), indicated that the MRformulation avoided a spike in the concentration of serum25-hydroxyvitamin D₃. The relative bioavailability of the MR formulationwhen compared to the IR formulation was approximately 77%. Animalsreceiving the MR formulation exhibited a mean T_(max) of 26.5 hrs whichindicated a significant delay compared to the animals receiving the IRformulation (T_(max)=5.75 hrs).

Exposure was assessed in animals receiving 1×250 μg MR capsules on Days1, 2 and 3. The mean increase in concentration of 25-hydroxyvitamin D₃over baseline 24 h following dosing was 17.3, 31.5 and 43.9 ng/mLfollowing the first, second and third dose respectively.

FIG. 13 through FIG. 18 show the mean pharmacokinetic profile foranimals in Groups 1-6, respectively. FIG. 19 shows a comparison ofpharmacokinetic profiles for MR and IR formulations of 250 μg25-hydroxyvitamin D₃.

Example 3 Systemic Exposure Studies in Miniature Swine with OralCapsules

The purpose of this study was to assess the increase in systemic25-hydroxyvitamin D₃ concentrations in healthy normal male Yucatan swine(˜50-60 kg body weight) maintained on a diet including an adequateintake of Vitamin D, following the daily administration of thefollowing: a) 25 μg immediate release (IR) 25-hydroxyvitamin D₃ capsules(Group 1), b) 25 μg modified release (MR) 25-hydroxyvitamin D₃ capsules(Group 2), and c) 125 μg MR 25-hydroxyvitamin D₃ capsules (Group 3), for21 days.

The MR formulations were prepared based on the formulation of Example 1,Group 7, above. The differences in concentration of 25-hydroxyvitamin D₃were offset by relative changes in ethanol.

To prepare the IR formulation 25-hydroxyvitamin D₃ (0.12% wt/wt; 250 μgper capsule) was dissolved in ethanol USP (2.32% wt/wt; solublizer) andmixed with corn oil USP, (97.54% wt/wt; main vehicle) and butylatedhydroxytoluene (0.02% wt/wt; antioxidant). The corn oil solution (205mg) was filled into size 0 two piece hard gelatin capsules.

Eight male Yucatan miniature swine per group were each administered adaily dose based on the dosing schedule in Table 9, below.

TABLE 9 Number/ Group Gender of Dose ID Animals Route Dose/Animal 1M8/male Oral 1 × 25 μg, immediate release 25- hydroxyvitamin D₃ capsuledosed daily for 21 days 2M 8/male Oral 1 × 25 μg, modified release 25-hydroxyvitamin D₃ capsule dosed daily for 21 days 3M 8/male Oral 1 × 125μg, modified release 25- hydroxyvitamin D₃ capsule dosed daily for 21days

Blood was collected from animals prior to the first dose and daily at 24h following daily dose, prior to subsequent dose. The concentration ofserum 25-hydroxyvitamin D₃ was assayed using solid-phase extraction(SPE) with high performance liquid chromatography with tandem massspectrometry (LC-MS/MS) detection. Total serum calcium was determined insamples collected from animals at the following time points: pre dose(Day 0) and 24 h following last dose (Day 21).

In all three groups, pre-dose mean serum 25-hydroxyvitamin D₃concentrations were approximately 26 ng/mL. After 21 doses, an increasein serum 25-hydroxyvitamin D₃ was observed in all animals. Following therepeat administration of 25 μg MR or IR capsules, the concentration ofserum 25-hydroxyvitamin D₃ increased to levels above 30 ng/mL and beganto plateau at approximately 45 and 55 ng/mL, respectively atapproximately Day 17 to 18. Upon the administration of a single dose,the increase in serum 25-hydroxyvitamin D₃ between the two regimens wascomparable (3.84 versus 4.18 ng/mL). On the other hand, at thecompletion of dosing the increase was approximately 60% greater foranimals administered the IR formulation. This finding indicates that thebioavailability from the MR capsule is comparable to that of the IRfollowing a single dose, but that the MR capsules present a method forrepeat dosing of 25-hydroxyvitamin D₃ in which systemic25-hydroxyvitamin D₃ can be gradually increased.

Animals administered 125 μg MR capsules exhibited higher levels of serum25-hydroxyvitamin D₃. The administration of a 5 fold greater dose (125μg versus 25 μg MR capsules) resulted in approximately 5 fold greaterincrease in 25-hydroxyvitamin D₃ following single and repeated dose.This finding indicates that exposure from MR capsules is doseproportional from 25 to 125 μg.

The effect of the administration of IR and MR capsules on theconcentration of serum calcium was investigated. After theadministration of 21 doses of either IR or MR, the levels of calcium inserum did not change from pre-dose baseline levels. This findingindicates that 25-hydroxyvitamin D₃ MR capsules can be utilized toincrease serum 25-hydroxyvitamin D₃ levels to above 100 ng/mL withoutcausing an increase in serum calcium.

Mean uncorrected serum 25-hydroxyvitamin D₃ concentration versus timeprofiles for Groups 1 to 3 are illustrated in FIG. 20. Mean baselinecorrected serum 25-hydroxyvitamin D₃ concentration versus time profilesfor Groups 1 to 3 are illustrated in FIG. 21, FIG. 22, and FIG. 23,respectively.

FIG. 24 shows the mean change in parathyroid hormone levels for Group 1animals from predose to day 21, and FIG. 25 shows the mean change inparathyroid hormone levels for Group 2 animals from predose to day 21.Immediate release and MR formulations both raise serum 25-hydroxyvitaminD₃; however, the immediate release formulation results in undesirablepharmacological decreases in PTH. The MR formulation does not effectacute supraphysiological reductions in PTH and allows for gradual PTHlowering, believed to be associated with physiological adaptation tomarkedly rising 25-hydroxyvitamin D₃ levels. The MR formulation shouldpermit attainment of higher serum 25-hydroxyvitamin D₃ levels withoutsafety concerns associated with undesirable pharmacological lowering ofPTH.

Example 4 Pharmacokinetic Studies in Beagle Dogs with Oral Capsules

Modified release 25-hydroxyvitamin D₃ capsules were administered dailyto Beagle dogs (10 kg) for 13 consecutive weeks. The MR formulationswere prepared based on the formulation of Example 1, Group 7, above. Thedifferences in concentration of 25-hydroxyvitamin D₃ were offset byrelative changes in ethanol.

The capsules were administered orally, as shown in Table 10 below.

TABLE 10 Nominal Dose Level Dose/ Treatment (μg/kg/day), based CapsuleNumber of Group on 10 kg ave. weight (μg) Capsules 1. Control 0 0 1Group (placebo) 2. Low Dose 2.5 25 1 3. Mid-Low 12.5 125 1 Dose 4.Mid-High 50 500 1 Dose 5. High Dose 100 1000 1

Dogs were bled prior to the first dose and at specific time pointsfollowing the first dose, up to 13 weeks (92 days). Serum was generatedand 25-hydroxyvitamin D₃ was assayed in the serum using a liquidchromatography tandem mass spectrometry method.

Mean serum 25-hydroxyvitamin D₃ concentration versus time profiles forGroups 1 to 5 are illustrated in FIG. 26.

Example 5 Release Upon Dissolution

FIG. 27 shows a dissolution release profile for 250 μg capsulesaccording to Example 2 above, which showed an average release of about72% of 25-hydroxyvitamin D₃ at 24 hours. As described above, preferablythe modified release formulation releases about 80% of the drug in thefirst 24 hours.

Example 6 Efficacy Study in Healthy Adult Male Volunteers with Vitamin DInsufficiency

The effectiveness of three different formulations of Vitamin D inrestoring serum 25-hydroxyvitamin D to optimal levels (>30 ng/mL) isexamined in a 23-day study of healthy non-obese men diagnosed withVitamin D insufficiency. One of the formulations (Formulation #1) is asoft gelatin capsule containing 30 μg of 25-hydroxyvitamin D₃ preparedas described in Example 1, Group 7, above. The second formulation(Formulation #2) is an immediate-release soft gelatin capsule ofidentical appearance containing 50,000 IU of ergocalciferol dissolved inmedium chain triglyceride oil. The third formulation (Formulation #3) isan immediate-release soft gelatin capsule, also of identical appearance,containing 50,000 IU of cholecalciferol dissolved in medium chaintriglyceride oil. A total of 100 healthy Caucasian and African-Americanmen participate in this study, all of whom are aged 30 to 45 years andhave serum 25-hydroxyvitamin D levels between 15 and 29 ng/mL(inclusive). All subjects abstain from taking other Vitamin Dsupplements for 60 days before study start and continuing through studytermination, and from significant sun exposure. On Day 1 and 2 of thestudy, all subjects provide fasting morning blood samples to establishpre-treatment baseline values of serum 25-hydroxyvitamin D. On themorning of Day 3, the subjects provide an additional fasting bloodsample (t=0), are randomly assigned to one of four treatment groups, andare dosed with a single test capsule prior to eating breakfast: thesubjects in Group #1 each receive a single capsule of Formulation #1,and the subjects in Groups #2 and #3 each receive a single capsule ofFormulation #2 or Formulation #3, respectively. Subjects in Group #4receive a matching placebo capsule. Subjects in Group #1 each receive anadditional capsule of Formulation #1 on the mornings of Days 4 through22 before breakfast, but subjects in Groups #2, #3 and #4 receive noadditional capsules. A fasting morning blood sample is drawn from eachsubject, irrespective of treatment group, on Days 4, 5, 6, 10, 17 and 23(or 1, 2, 3, 7, 14 and 20 days after the start of dosing). All collectedblood is analyzed for the contained levels of 25-hydroxyvitamin D, andthe data are analyzed by treatment group after correction for baselinevalues. Subjects in all four treatment groups exhibit mean baselineserum 25-hydroxyvitamin D levels of approximately 16 to 18 ng/mL, basedon analysis of fasting blood samples drawn on Days 1 through 3. Subjectsin Group #4 (control group) show no significant changes in mean serum25-hydroxyvitamin D over the course of the study. Subjects in Group #1show a steadily increasing mean serum 25-hydroxyvitamin D reaching atleast 30 ng/mL by Day 23. In marked contrast, subjects in Group #2exhibit marked increases in mean serum 25-hydroxyvitamin D for the firstfew days post-dosing, reaching a maximum of 29 ng/ml and then rapidlydeclining thereafter. By study end, serum 25-hydroxyvitamin D issignificantly lower than baseline in Group #2. Subjects in Group #3exhibit continuing increases in mean serum 25-hydroxyvitamin D throughthe first 2 weeks after dosing with gradual, but progressive, decreasesoccurring thereafter. By study end, mean serum 25-hydroxyvitamin D isbelow 30 ng/mL, being only approximately 11 ng/mL higher thanpre-treatment baseline. The data from this study demonstrate thatadministration of 600 μg of 25-hydroxyvitamin D₃, formulated asdescribed herein and administered at a dose of 30 μg per day for 20days, is substantially more effective in restoring low serum levels of25-hydroxyvitamin D to optimal levels than immediate-releaseformulations of 50,000 IU of either ergocalciferol or cholecalciferoladministered in single doses, as currently recommended by the NKF andother leading experts on oral Vitamin D replacement therapy.

Example 7 Efficacy Study in Patients with Stage 4 CKD and SecondaryHyperparathyroidism Associated with Vitamin D Insufficiency

The effectiveness of oral immediate-release and modified-release25-hydroxyvitamin D₃ in restoring serum total 25-hydroxyvitamin D tooptimal levels (>30 ng/mL) and is examined in a 6-month study of adultmale and female patients with Stage 4 CKD and secondaryhyperparathyroidism associated with vitamin D insufficiency. Twoformulations are used in the study. One of the formulations (Formulation#1) is a soft gelatin capsule containing 40 μg of 25-hydroxyvitamin D₃in a modified-release formulation. The second formulation (Formulation#2) is a soft gelatin capsule containing 40 μg of 25-hydroxyvitamin D₃in an immediate-release formulation. A total of 100 subjects participatein this study, all of whom are aged 30 to 70 years and have serum25-hydroxyvitamin D levels between 15 and 29 ng/mL (inclusive) and serumintact parathyroid hormone (iPTH) levels above the target levelspublished in the current K/DOQI Guidelines at the time of enrolment. Allsubjects abstain from taking other Vitamin D supplements for 60 daysbefore study start and continuing through study termination, and fromsignificant sum exposure. All subjects begin daily dosing with twocapsules of either Formulation #1 or Formulation #2. Serum total25-hydroxyvitamin D is measured at biweekly intervals and serum iPTH isdetermined at quarterly intervals. After 1 month, the daily dosage ofboth Formulations is maintained unchanged in patients whose serum total25-hydroxyvitamin D is between 50 and 90 ng/mL, increased by one capsulein patients whose serum total 25-hydroxyvitamin D is below 50 ng/mL, anddecreased by one capsule per day in patients whose serum total25-hydroxyvitamin D is above 90 ng/mL. Further adjustments in the dailydose are made in order to maintain serum total 25-hydroxyvitamin Dbetween 50 and 90 ng/mL. Dosing with both Formulation #1 and #2 iscontinued indefinitely, provided that hypercalcemia, hypercalciuria andhyperphosphatemia do not develop, in which case appropriate adjustmentsin dosage are made. After 6-months, the subjects' serum total25-hydroxyvitamin D levels are found to remain stable between 50 and 90ng/mL with treatment with Formulation #1 and serum iPTH is found toremain stable at levels consistent with targets published in the K/DOQIGuidelines. The incidence of hypercalcemia, hypercalciuria andhyperphosphatemia are rare once stable dosing has been achieved. Incontrast after 6-months, the subjects' serum total 25-hydroxyvitamin Dlevels are not found to remain stable between 50 and 90 ng/mL withtreatment with Formulation #2 and serum iPTH does not reach levelsconsistent with targets published in the K/DOQI Guidelines. Theincidence of hypercalcemia, hypercalciuria and hyperphosphatemia aresubstantial.

Data from this study demonstrate that the modified release formulationof 25-hydroxyvitamin D₃ is effective at increasing serum25-hydroxyvitamin D without causing unacceptable side effects related tocalcium and PTH metabolism.

The foregoing description is given for clearness of understanding only,and no unnecessary limitations should be understood therefrom, asmodifications within the scope of the invention may be apparent to thosehaving ordinary skill in the art.

Throughout the specification, where compositions are described asincluding components or materials, it is contemplated that thecompositions can also consist essentially of, or consist of, anycombination of the recited components or materials, unless describedotherwise.

The practice of a method disclosed herein, and individual steps thereof,can be performed manually and/or with the aid of electronic equipment.Although processes have been described with reference to particularembodiments, a person of ordinary skill in the art will readilyappreciate that other ways of performing the acts associated with themethods may be used. For example, the order of various of the steps maybe changed without departing from the scope or spirit of the method,unless described otherwise. In addition, some of the individual stepscan be combined, omitted, or further subdivided into additional steps.

1. A method of treating secondary hyperparathyroidism in Chronic KidneyDisease (CKD) Stage 3 or Stage 4 in a human patient, comprisingadministering to the patient an effective amount of a controlledrelease, oral dosage form of 25-hydroxyvitamin D to reduce the subject'sserum parathyroid hormone level by at least 30% while safely raisingserum total 25-hydroxyvitamin D.
 2. The method of claim 1, wherein thesubject is vitamin D insufficient or vitamin D deficient.
 3. The methodof claim 2, wherein said effective amount of the controlled release,oral dosage form of 25-hydroxyvitamin D is also effective to increasethe subject's serum total 25-hydroxyvitamin D level to at least 30ng/mL.
 4. The method of claim 3, wherein said effective amount of thecontrolled release, oral dosage form of 25-hydroxyvitamin D is alsoeffective to increase the subject's serum total 25-hydroxyvitamin Dlevel to a value in a range of 50 ng/mL to 90 ng/mL.
 5. The method ofclaim 1, wherein the subject's plasma intact parathyroid hormone levelis reduced to the target range for the CKD Stage.
 6. The method of claim1, wherein the 25-hydroxyvitamin D is selected from the group consistingof 25-hydroxyvitamin D2, 25-hydroxyvitamin D₃, and a combination of25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃.
 7. The method of claim 6,wherein the 25-hydroxyvitamin D is 25-hydroxyvitamin D₃.
 8. The methodof claim 1, comprising administering said oral dosage on a schedule ofonce per day.
 9. The method of claim 8, wherein the daily dose is in arange of 1 μg to 1000 μg.
 10. The method of claim 1, wherein the dailydose of 25-hydroxyvitamin D is in a range of 1 μg to 1000 μg.
 11. Themethod of claim 1, wherein the amount of 25-hydroxyvitamin D in thecontrolled release, oral dosage form is in a range of 1 μg to 1000 μgper unit dose.